2. 02
Metrohm ...
• is the global market leader in titration
• is the only company to offer a complete range of ion analysis equipment – titration,
voltammetry, and ion chromatography
• is a Swiss company and manufactures exclusively in Switzerland
• grants a 3year instrument warranty and a 10year warranty on chemical suppressors for
ion chromatography
• provides you with unparalleled application expertise
• offers you more than 1300 applications free of charge
• supports you with expert service through local representatives and regional support centers
• is not listed on the stock exchange, but is owned by a foundation
• gives the interest of customers and employees priority over maximizing profit
3. Metrohm – customized analysis for the petrochemical
industry
A demanding industry
It is a long way from crude oil to the innumerous prod
You can count on our support
Not only do we provide you with the right instrumenta
03
ucts made from it. The industrial refining processes are tion but with complete solutions for the particular task at
demanding. hand. Your partners at Metrohm are experienced pro-
fessionals who help you with customized application
As a leading solution provider to the petrochemical in support and service.
dustry, we are quite aware of these challenges. We offer
you state-of-the-art instrumentation helping you to On the following pages, discover the solutions Metrohm
check and improve the quality of petrochemical products offers the petrochemical industry in general and you
and comply with the standards – in your laboratory but in particular, to ensure the quality and safety of your
also atline and online in the process environment. products.
4. Analysis of petroleum products
04 Formation of crude oil deposits
According to current knowledge our oil reserves origi
«Lubricant» of the global economy
Nowadays crude oil, which consists of at least 500 differ
nated during the Jurassic and Cretaceous periods (200 to ent components, is processed by distillation and refining
65 million years ago) from microbial flora and fauna liv to liquid gas, gasoline, diesel, and heating fuel, lubricants
ing in the seas. While some of the dead organic residues as well as a large variety of other products. As the «lubri
were directly mineralized, i.e. decomposed, the other cant» of the global economy, crude oil is omnipresent.
part sank to the seabed. There the material was covered It covers approximately 40% of our energy demand and
by other marine deposits and formed a sludge with very is used in the chemical industry for the production of
fine rock material that slowly converted to crude oil plastics, textiles, and dyes, cosmetics, fertilizers, detergents,
under the prevailing biogeochemical conditions of in building materials, and pharmaceuticals.
creased pressure and salinity. Due to its lower density the
crude oil migrated upwards through fine cracks in the The importance of the petroleum products and their
rock layers until it accumulated under impermeable cov derivatives is reflected by the large number of standards
ering rocks and thus formed the oil deposits we know relating to them. Metrohm as a leading manufacturer of
today. Sometimes aboveground oil deposits were for instruments for ion analysis offers longstanding applica
med that already allowed our forefathers to use crude oil tion knowhow for the quality assurance of petroleum
for heating and lighting, building, or lubrication. products.
5. Selected standards from the field of petrochemical
analysis
The standards listed below describe numerous interna-
tional testing and requirement specifications for petro-
minimum requirements and limits stipulated by the res
pective standards.
05
leum products. Metrohm instruments comply with all the
Parameter Standard Matrix Method Page
Petroleum products
ASTM D 4739 Potentiometric titration
Base number Lubricants
ASTM D 2896 Petroleum products Potentiometric titration
Total base number DIN ISO 3771 Petroleum products Potentiometric titration
Nitrogenous bases UOP269 Petroleum distillates Potentiometric titration
Acid and base number ASTM D 974 Petroleum products Colorimetric titration 6
ASTM D 664 Petroleum products Potentiometric titration
Acid number DIN EN 12634 Petroleum products Potentiometric titration
Lubricants
Petroleum products
Acid number and naphthenic acids UOP565 Potentiometric titration
Petroleum distillates
ASTM D 3227 Automotive fuel, kerosene Potentiometric titration
Mercaptan sulfur Highly volatile distillates
ISO 3012 Potentiometric titration
Moderately volatile distillates
H2S ASTM D 2420 Liquefied petroleum gas (LPG) Potentiometric titration
8
H2S, mercaptan sulfur UOP163 Petroleum products Potentiometric titration
Used alkaline petroleum
Alkalinity, H2S, mercaptans UOP209 Potentiometric titration
products
H2S, mercaptan sulfur, Gaseous hydrocarbons
UOP212 Potentiometric titration
carbonyl sulfide Liquefied petroleum gas (LPG)
ASTM D 94 Petroleum products Potentiometric titration
Saponification number DIN 51559 Crude oil 9
Colorimetric titration
Insulating oil
ASTM D 1159 Petroleum distillates Potentiometric titration
Bromine number Aliphatic alkenes
ASTM D 5776 Aromatic hydrocarbons Potentiometric titration
ISO 3839 Petroleum distillates 10
Potentiometric titration
Alkenes
Bromine number and bromine index UOP304 Hydrocarbons Potentiometric titration
Bromine index ASTM D 2710 Petroleum hydrocarbons Potentiometric titration
ASTM E 1899 Aliphatic and cyclic Potentiometric titration
hydrocarbons
Hydroxyl number 10
DIN 53240 Resins, raw materials for varnishes, Potentiometric titration
primary alcohols, glycols, fat
Organic, inorganic and UOP588 Hydrocarbons Potentiometric titration
total chlorine content 11
Organic chlorine content ASTM D 4929 Crude oil Potentiometric titration
Salinity ASTM D 6470 Crude oil Potentiometric titration 11
a Petroleum hydrocarbons Coulometric KFTb
51777-1/2 DIN Solvents Volumetric KFT
ASTM D 4377 Crude oil Volumetric KFT
ASTM D 4928 Crude oil Coulometric KFT
Crude oil
ASTM E 1064 Organic solvents Coulometric KFT
Water content Lubricating oil
ASTM D 6304 Petroleum products Coulometric KFT 12
ASTM D 1364 Highly volatile solvents Volumetric KFT
ASTM D 890 Turpentine Azeotropic distillation, KFT
ASTM E 203 General Volumetric KFT
ISO 10336 Crude oil Volumetric KFT
ISO 10337 Crude oil Coulometric KFT
ISO 12937 Petroleum products Coulometric KFT
ISO 6296 Petroleum products Volumetric KFT
EN 14112 Fatty acid methyl esters (B100) Oxidation stability
Oxidation stability 15751 Fatty acid methyl esters 14
EN
Diesel fuel blends Oxidation stability
DIN EN 15492,
Ethanol as a blending
Inorganic chloride and sulfate ASTM D 7319, Ion chromatography 16
component in gasoline
ASTM D 7328
Free and total glycerol contentC ASTM D 7591 Biodiesel blends Ion chromatography 16
Sulfur, heavy metals – Gasoline, ethanol Voltammetry 22
pH value, conductivity, and Process-dependent
parameters that can be determined conditions Petroleum products Process analysis 24
by titration and voltammetry
a
in revision, bKarl Fischer titration, cTest methods for the biofuel sector can be found in the brochure «Biofuel analysis» (8.000.5013EN).
6. Determination of acid and base numbers
06 Potentiometric titration with the Solvotrode
With the base number, alkaline components are deter- The Solvotrode easyClean is a combined pH glass elec
mined in petroleum products as a sum parameter. These trode that was especially developed for this app li
include primary organic and inorganic amino compounds cation. The separable ground-joint diaphragm can be
in particular. However, salts of weak acids, basic salts of easily clean even of strong contamina ion. The
ed t
polycarboxylic acids, a number of heavy metal salts, and electrostatic shielding of the elecro com
t lyte
detergents are also recorded. The base number indicates partment also ensures a low-noise meas uring
how many basic components, expressed as mg KOH, are signal.
contained in 1 g of sample. This determination is used for
the im diate detection of product changes during use.
me
With the acid number, acidic components are measured
in petroleum products as a sum parameter. These are
com
pounds (acids, salts) with pKa values < 9. The acid
num indicates how many mg KOH are required to
ber
neutralize 1 g of sample. The acid number indicates
changes during the use of the product. Both parameters
are determined by potentiometric titration in nonaque
ous solvents or solvent mixtures. Titrimetric determina
tions can be completely automated – from the addition
of solvents to the cleaning of the electrode. Oil samples
can even be weighed in fully automatically by the 864
Robotic Balance Sample Processor before titration. This
guarantees complete traceability.
Solvotrode easyClean
Determination of acid and base number according
to ASTM D 974 (photometric detection)
The acid and base number may also be deteremined in a
photometric titration with color indication of the equiva
lence point according to ASTM D 974. For this applica
tion, Metrohm offers the Optrode, a new sensor for
pho metric titration. It is 100% solvent resistant (glass
to
shaft) and – unlike visual endpoint recognition – enables
automation of the determination.
Optrode
7. Standard Parameter Titrant Solvent Electrode 07
(reference electrolyte)
Chloroform, toluene, Solvotrode easyClean
ASTM D 4739 Base number HCl in isopropanol
isopropanol, water (LiCl in EtOH)
Base number Perchloric acid in Solvotrode easyClean
ASTM D 2896 Glacial acetic acid, xylene
>300 mg KOH/g glacial acetic acid (TEABra in ethylene glycol)
Perchloric acid in Toluene, glacial acetic acid, Solvotrode easyClean
DIN ISO 3771 Total base number
glacial acetic acid acetone (TEABr in ethylene glycol)
Toluene, isopropanol,
Solvotrode easyClean
ASTM D 664 Acid number KOH in isopropanol water (lubricants)
(LiCl in EtOH)
Isopropanol (biodiesel)
b Dimethylsulfoxide, Solvotrode easyClean
DIN EN 12634 Acid number KOH in TMAH
isopropanol, toluene (LiCl in EtOH)
Acid number and Toluene, isopropanol, Solvotrode easyClean
UOP565 KOH in isopropanol
naphthenic acids water (LiCl in EtOH)
ASTM D 974 Acid Number KOH in isopropanol Toluene/isopropanol/water Optrode
ASTM D 974 Base Number HCl in isopropanol Toluene/isopropanol/water Optrode
a
Tetraethylammonium bromide
b
Tetramethylammonium hydroxide
855 Robotic Titrosampler (with 772 Pump Unit) for TAN/TBN determination
8. 08 Sulfur and sulfur compounds determined by
potentiometric titration with the Ag-Titrode
Sulfur compounds contained in petroleum products not
only have an unpleasant odor, they are also environmen
tally damaging and promote corrosion. For determining
hydrogen sulfide and mercaptans in liquid hydrocarbons
(gasoline, kerosene, naphtha, and similar distillates), the
sample is titrated with silver nitrate solution, whereby
silver sulfide (Ag2S) and silver mercaptide are produced.
Two pronounced potential jumps occur. The first end
point corresponds to hydrogen sulfide (H2S), the second
to the mercaptans. The indicator electrode for the titra-
tion is the Ag-Titrode, version with Ag2S coating. Since
both H2S and mercaptans are oxidized by atmospheric
oxygen and the arising oxidation products cannot be
determined titrimetrically, work must be carried out un
der
a nitrogen atmosphere.
Gaseous sulfur compounds can also be determined with
this procedure. For this purpose, they are absorbed in an
alkaline solution. The first two absorption vessels contain
KOH or NaOH (for H2S and mercaptans), the third con
tains ethanolic monoethanolamine (for carbonyl sulfide).
The results are expressed in mg/kg (ppm) hydrogen sul- Ag-Titrode
fide and/or mercaptan sulfur.
9. Thermometric titration
Instrumental methods using a glassmembrane pH elec
09
trode suffer from the difficulty of working in a waterfree
environment of very low electrical conductivity where the
glass membrane is rapidly dehydrated or the sensor is
contaminated by the sample. This results in a need for
timeconsuming sensor maintenance, which has to be
carried out with high reproducibility.
Similarly, the determination of TBN involves a nonaque
ous titration of the weakly basic substances contained in
the additive packages using strong acids diluted in suit
able solvents. Typically, perchloric acid in glacial acetic
acid is used as the titrant. Glass membrane potentiomet-
ric sensors suffer similar problems in the determination of
TBN as during the TAN determination.
The alternative thermometric titration procedure over Catalytically enhanced thermometric titration: after the
comes the above mentioned problems. It is based on the endpoint has been reached, the excess hydroxide ions catalyze
principle, that every chemical reaction is accompanied by the endothermic hydrolysis of the added paraformaldehyde.
a change in enthalpy (∆H). As long as the reaction takes
place, this results in either an increase (exothermic reac
tion) or decrease (endothermic reaction) in the tempera
ture of the sample solution, which is indicated by a very
sensitive temperature sensor. For TAN and TBN, this is
enhanced by the use of special chemical thermometric
indicators. The method can also be fully automated and
titration times are approximately three times faster than
their potentiometric titration counterparts. Less solvent
and no special sensor maintenance is required.
10. 10 Saponification number
The saponification number (SN) primarily serves to deter The method is used for the following products:
mine the proportion of fatty acid esters in the sample. • Distillates with a boiling point below 327 °C (620 °F)
The fatty acid esters are cleaved by boiling in KOH, a and a volume percentage of at least 90% of com
process which produces the salts of the fatty acids and pounds that are lighter than 2-methylpropane (inclu
d
the corresponding alcohol, for example, glycerol. The ed in this are fuels with and without lead additions,
method is not specific since acidic sample constituents kerosene and gas oils).
consume KOH and in so doing increase the saponifica • Commercial alkenes (mixtures of aliphatic monoalke
tion number (SN). The titrant employed is c(HCl) = 0.5 mol/L nes) with a bromine number from 95 to 165.
in isopropanol. The SN indicates how many mg KOH are • Propenes (trimers and tetramers), butene trimers, mix
consumed by 1 g sample under the test conditions. tures of nonenes, octenes, and heptenes.
Bromine number and bromine index The BI indicates how many mg of bromine (Br2) are
The bromine number (BN) and the bromine index (BI) bound by 100 g of sample. The method is used for
indicate the proportion of unsaturated compounds «alkene-free» hydrocarbons with a boiling point below
(usually C-C double bonds) in petroleum products. Here, 288 °C (550 °F) and a bromine index of between 100
the double bond is cleaved by bromine addition. The BN and 1000. For products with a bromine index of >1000
in
dicates how many g of bromine (Br2) are bound by the bromine number should be used.
100 g of sample.
Method Samples Titrant Solvent Electrode
Automotive fuels, kerosene, c(bromide/ Glacial acetic acid,
Bromine number Double
gas oils, propene, butenes, bromate solution) = trichloroethane,
[g Br2/100 g] Pt-wire electrode
heptenes, octenes, nonenes 0.08333 mol/L methanol
c(bromide/ Glacial acetic acid,
Bromine index Double
Olefin-free hydrocarbons bromate solution) = trichloroethane,
[mg Br2/100 g] Pt-wire electrode
0.00333 mol/L methanol
11. 11
Hydroxyl number Chloride and organically bound chlorine
The hydroxyl number (OHN) indicates the number of Organically bound chlorine present in petroleum prod
mg KOH corresponding to the hydroxyl groups in 1 g ucts is decomposed at high temperatures and forms
sample. The most frequently described method for de hydrochloric acid, which is highly corrosive and can
termining the hydroxyl number is conversion of the cause damage, for example, to the distillation columns.
sample with acetic acid anhydride in pyridine with subse
quent titration of the released acetic acid. The one-hour Before measurement, the sample is freed of sulfur com
boiling under reflux, the difficulty in automating the pounds and inorganic chlorides by distillation and subse
process and particularly the use of the health-hazardous quent washing as described in ASTM D 4929. The organ
pyridine are serious disadvantages. i
cally bound chlorine is converted to NaCl with metallic
sodium in toluene. After extraction into the aqueous
An alternative is offered by the considerably simpler phase the NaCl is titrated potentiometrically with silver
and more easily automated method according to ASTM nitrate solution.
E 1899. Primary and secondary hydroxyl groups are con
verted with toluene-4-sulfonyl-isocyanate (TSI) into an
acid carbamate, which is then titrated with the strong
base tetrabutylammonium hydroxide (TBAH) in a non-
aqueous medium. The method is especially suitable for
neutral raffinates. Acidic products can falsely indicate too
high values. In the same way products that contain bases
can show too low values due to neutralization of the
carbamate formed.
In comparison to the formerly used 1-hour boiling under
reflux, this automated procedure is much more time sav
ing, convenient, and reproducible, as it gurantees that
every sample is treated in exactly the same way.
12. Water determination according to Karl Fischer
12 Water occurs as a contaminant in virtually all petroleum
products. It reduces lubricant properties, promotes micro
Hydraulics, insulation, transformer and turbine oils
In these oils the water content is almost always deter-
bial
oil degradation, leads to sludge formation in the mined coulometrically using a diaphragm cell. Due to the
tank, and promotes corrosion of ferrous and nonferrous poor solubility in methanol, solubilizers must be used
meals. While at higher temperatures water boils and
t (chloroform or trichloroethylene). Since these products
conrib tes to a partial degreasing, temperatures be
t u low feature a very low water content, it is very important to
free
zing point lead to the formation of ice crystals and a achieve a low and constant drift value.
rapid decrease in lubricity. In addition, insulating and
transformer oils used in high-voltage engineering become Engine oils, lubricating oils, and lubricating greases
electrically conducting and are therefore rendered use The additives frequently present in these oil samples can
less in the presence of water. react with KF reagents and falsify the result. If a KF drying
oven is used, a stream of dry carrier gas transfers the
In view of this, knowledge of the water content in petro expelled water into the titration cell. Since the sample
leum products is of prime importance. Karl Fischer titra- itself does not come into contact with the KF reagent,
tion, owing to its excellent reproducibility and accuracy interfering side reactions and matrix effects can be ex-
as well as its ease of use, numbers amongst the most cluded. The correct heating temperature lies below the
important water determination methods and accordingly de composition temperature of the sample and is deter-
figures in numerous international standards. Meaures mined in preliminary tests.
ment can occur by volumetric or coulometric Karl Fischer
titration. Because of the low water content in pe
troleum Turpentine and its distillation products
products, KF coulometry is usually applied. After addition of toluene or xylene, the water is trans-
ferred by azeotropic distillation to the titration cell where
Aliphatic and aromatic petroleum components it is determined by Karl Fischer titration.
Water determination in these products is simple. They
usually contain only little water so that the coulometric
Karl Fischer titration is used. If volumetric titration has to
be carried out, reagents with a low titer must be used.
For long-chain hydrocarbons, the addition of a solubilizer
(propanol, decanol or chloroform) is recommended to
improve solubility. In the rare case of interferences by
double bonds, the use of one-component reagents is
recommended.
KF Evaporator 860 KF Thermoprep with 851 Titrando
13. 13
Petroleum (crude oil, heavy oil)
Water is not homogeneously distributed in these prod
ucts, so that the petroleum samples must first be homog
enized before analysis, for example, with the Polytron PT
Reaction of a mercaptane with N-ethylmaleimide
1300D. Furthermore, crude and heavy oils contain tars
that can seriously contaminate electrodes and titration
cells. Reagents must therefore be exchanged regularly
and the titration cells must be cleaned frequently. In or
der to ensure that the sample completely dissolves, solu Mobile coulometry with the 899 Coulometer
bilizers are added to the methanol: There are situations where a quick determination of the
water content is required but the laboratory is far and
• Crude oil (in general) 10 mL methanol + 10 mL wating for results is out of the question. There might be
chloroform + 10 mL toluene no socket around to plug in a power cord either. For si
tu
• Heavy oil 10 mL methanol + 10 mL a
tions like this, the compact 899 Coulometer comes with
chloroform + 20 mL toluene an optional Power Box. It contains a set of recharchable
batteries lasting for hours of uninterrupted operation.
Fuels
This group contains mercaptans that are oxidized by iod
ine and thus produce too high water contents. The prob
lem is dealt with by adding N-ethylmaleimide, which
causes the SH groups of the mercaptan to attach them
selves to the double bond of the N-ethylmaleimide.
899 Coulometer and
optional Power Box
Another option is the separate determination of the mer
captan component by potentiometric titration with silver
nitrate. The result of the water determination reduced by
this amount corresponds to the actual water content of
the sample (1 ppm mercaptan sulfur corresponds to ap
prox. 0.5 ppm water). Normally the water content in
fuels is determined by coulometric titration. With volume
tric titration a solubilizer must be added to the methanol.
14. Oxidation stability
14 If stored in such a way that air has access, petroleum
undergoes oxidizing reactions whose reaction products
driven out by the air current, absorbed in water and
detected there by measuring the conductivity. The time
can lead to problems in combustion engines. Polymers until formation of these decomposition products occurs
and poorly soluble com pounds in particular lead to de- is referred to as the induction time or the Oil Stability
posits in and block ges of the fuel injector systems. The
a Index (OSI) and characterizes the resistance of the
aging behavior (oxidation stability) is therefore a very sample towards oxidative aging processes, i.e. the oxida
important property of petroleum products. tion stability.
In order to quantitatively determine the oxidation stabil 873 Biodiesel Rancimat
ity using the Rancimat method, air is passed through the The 873 Biodiesel Rancimat allows the simple and re-
sample to be examined at an elevated temperature to liable determination of oxidation stability in petroleum
bring about artificial aging. During this process long- products and biodiesel. The device is controlled via a PC;
chain organic molecules are oxidized by oxygen, the PC software records the measurement curves, auto
wher by highly volatile organic substances form in addi
e matically evaluating them and calculating the result. Up
tion to insoluble polymer compounds. The former are to eight samples can be measured simultaneously.
15. 15
Important applications
Biodiesel and biodiesel blends
Biodiesel (FAME, fatty acid methyl esters) is usually ex- free diesel fuel is appearing more and more on the market
trac from oilseeds by transesterification with methanol.
ted (ultra-low-sulfur diesel). This mineral diesel fuel with a sulfur
It is being added more and more to mineral diesel as a content of at most 10 ppm (EU) or 15 ppm (USA) is oxidized
blending component. Vegetable oils and methyl esters of considerably more easily than the formerly used diesel fuels
fatty acids are relatively unstable under storage conditions with a higher sulfur content. This means that oxidation
since they are slowly oxidized by atmospheric oxygen. Just stability has also become an important parameter for fuel
as with oxidation of petroleum, polymer compounds are production. The 873 Biodiesel Rancimat allows a simple
formed during the oxidizing of biodiesel that can cause assess
ment of oxidation stability.
da
mage to engines. For this reason, oxidation stability is an
important quality criterion for biodiesel and vegetable oils Biologically easily degradable lubricating oils
that must be controlled regularly during production accord Biologically easily degradable lubricants can also be manu
ing to EN 14112. The corresponding method for biodiesel factured from natural fat and oils. Like the raw material,
blends is described in EN 15751. The addition of suitable these products are also susceptible to oxidation.
antioxidants slows down the oxidation process. The 873
Biodiesel Rancimat also allows to determine the effective- Heating oil
ness of antioxidants. Alongside other methods the Rancimat method is also used
for assessing the oxidation stability of light fuel oil. In order
Ultra-low sulfur diesel fuel to accelerate the reaction, metallic copper is added to the
As a result of environmental protection concerns and tech fuel oil sample to act as a catalyst.
nical requirements for motor vehicle manufacturers, sulfur-
16. 16
Ion chromatographic analyses
The quality assurance of petroleum products involves
numerous applications of ion chromatography in which
inorganic and low-molecular organic ions are determined
in fuels, lubricating oils, gas-washing solutions and the
so-called «Produced water» that is a by-product of crude
oil drilling.
Anions and cations in «Produced water»
During oil production large quantities of «Produced
water» are transported to the surface. In addition to oil
drops and dissolved organic components, «Produced
water» contains large amounts of inorganic cations such
as calcium, magnesium, barium, and strontium as well as
anions such as carbonate, bromide, and sulfate. The
resulting salts can cause scaling and ultimately block the
piping. For this reason, the determination of inorganic
components is of essential importance, last but not least
also for the correct dosing of scale inhibitors.
17. Since determinations occur not only on-shore, but also
off-shore, robust analytical devices that do not need to
17
be serviced frequently are required. This is offered by the
881 Compact IC pro in combination with the 858 Pro
fessional Sample Processor. The system can also be
equip ped with the inline dialysis system patented by
Metrohm. The intelligent chromatography software
MagIC NetTM assumes control of the device, the data
management and the system monitoring and can, if
neessary, be configured as «One-button IC» for semi-
c
skilled personnel.
Anions in «Produced water»; column: Metrosep A Supp 4 - 250/
4.0 (6.1006.430); eluent: 1.8 mmol/L Na2CO3, 1.7 mmol/L NaHCO3,
1.0 mL/min; sample volume: 20 µL; sample dilution 1:20
Cations in «Produced water»; column: Nucleosil 5SA - 125/4.0
(6.1007.000); eluent: 4.0 mmol/L tartaric acid, 3.0 mmol/L
ethylenediamine, 0.5 mmol/L dipicolinic acid, 5% acetone,
1.5 mL/min; sample volume: 20 µL; sample dilution 1:10
881 Compact IC pro in combination with 858 Professional Sample Processor,
optionally equipped with inline dialysis
18. 18
Anions in gasoline-ethanol blends
The use of energy from renewable sources and the asso
ciated reduction of greenhouse gases is one of the most
pressing goals of our modern industrial society. Ethanol
manufactured from waste and renewable plant material,
which can be mixed with conventional gasoline in any
proportion, is regarded as one of the most promising
alter
natives. Contaminants in the form of inorganic salts,
however, impair engine performance, so that various in
ternational standards now regulate particularly the chlo
ride and sulfate content of gasoline-ethanol blends.
Additional IC applications for petrochemistry
• Halogens and sulfur in liquefied natural gas (LNG)
and petroleum gas (LPG)
• Halogens, sulfur, and organic acids in crude oil, gasoline,
kerosene, heating oil, and coal (ASTM D 7359)
• Sulfur compounds in amine absorbens (heat stable
salts, HSS)
• Amines in various matrices from refineries and
petrochemical plants
• Anions, cations, and amines in process and waste
water samples and absorption solutions
• Alkali, alkaline earth and transition metals as well as
anions in cooling liquids, e.g., monoethyleneglycol
«MEG» (ASTM E 2469)
• Anions in emulsions from drilling oils
• Anions and cations in biofuels and fuel blends
19. Simple matrix elimination
The anions to be determined are freed from the inter- the preconcentration column using a rinsing solution.
19
fering fuel matrix by Metrohm Inline Matrix Elimination. Then the anions are eluted onto the analytical column.
For this purpose, the fuel is injected directly onto a high- This method allows the additional determination of ace
ca
pacity preconcentration column. While the anions are tate and formate.
retained on the column, the fuel matrix is removed from
Schematic representation of Metrohm Inline Matrix Elimination
Anions in an E85 gasoline-ethanol blend (85% ethanol, 15%
gasoline); column: Metrosep A Supp 7 - 250/4.0 (6.1006.630);
Eluent: 3.6 mmol/L Na2CO3, 7.5% acetone, 0.8 mL/min; column
temperature 45 °C; sample volume: 10 µL; matrix elimination:
transfer solution 7.5% acetone, sample preconcentration with
Metrosep A PCC 1 HC/4.0 (6.1006.310)
Anion system with Metrohm Inline Matrix Elimination
20. 20 Halogen and sulfur content: Combustion Ion
Chromatography
The burning of sulfur-containing fuels leads to the emis content is required. Combustion IC allows the determina
sion of air-polluting sulfur oxides into the atmosphere. tion of the sulfur and halogen content in combustible
Furthermore, high sulfur concentrations have an adverse solid and liquid matrices by combining combustion di
effect on the ease of ignition of fuels and their stability gestion (pyrolysis) with subsequent ion chromatography.
during storage. Additionally halogen concentrations in It can be fully automated and excels in its high sample
the raffinery steps from cride oil up to the final product throughput, large measuring range and excellent preci
have to be analyzed due to the corrosion risk. A fast and sion and accuracy.
reliable method for determining the halogen and sulfur
Combustion ion chromatography explained
Sample Combustion Absorbent Analysis
sulfur compounds SOX SO2-4 ion chromatography
halogen compounds HX, X2 X-
liquids
or
solids
oven
T > 900 °C
gas inlet
sample introduction combustion absorption analysis by IC
In combustion digestion (pyrolysis), sulfur compounds are converted into sulfur dioxide, and halogen compounds are converted into
hydrogen halides and elemental halogens. These gaseous combustion products are fed into an oxidizing absorption solution and
detected as sulfate and halide by way of the ion chromatography that follows.
21. 21
a) crude oil desalter
340
sulfate
320
280
Conductivity [µS/cm]
240
200
160 chloride;
1.1 mg/kg
120 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
Time [min]
80
chloride
40
0
0 2 4 6 8 10 12 14 16 18
Time [min]
Determination of the chlorine and sulfur content by Combustion IC in a) crude oil desalter output sample and b) B5 biodiesel blend;
column: Metrosep A Supp 5 - 150/4.0; eluent: 3.2 mmol/L Na2CO3, 1.0 mmol/L NaHCO3, 0.7 mL/min; column temperature: 30 °C;
sample volume: 100 μL
22. Voltammetry
22 Voltammetric trace analysis is used for determining elec
trochemically active substances. These can be inorganic
Voltammetry is suitable in particular for laboratories in
which, with a medium sample throughput, only a few
or organic ions or even neutral organic compounds. Vol parameters need to be controlled. It is often used for
t
ammetry is often used for supplementing and validating spe
cific applications that are either not feasible or too
spectroscopic methods and is characterized by low costly using other techniques.
equip
ment costs, comparably low investment and oper-
ating costs, short analysis times, and a high accuracy and 797 VA Computrace
sensitivity. Unlike spectroscopic methods, voltammetry The 797 VA Computrace is a modern voltammetric mea
can also differentiate between different oxidation states suring stand that allows voltammetric and polarographic
of metal ions or between free and bound metal ions. This determinations to be carried out. The analyses can also
is referred to as speciation analysis. be easily automated by adding Dosinos and a sample
changer.
Broad application range
Voltammetric measurements can be carried out both in
aqueous solutions and in organic solvents. Heavy metal
determinations are usually carried out in aqueous solu
tions after digestion of the sample.
23. 23
Interesting application examples
Elemental sulfur in gasoline Heavy metals in petroleum products
The total sulfur content in petroleum products is nor The determination of transition metals in petroleum pro
mally defined by law and is therefore routinely con- ducts by voltammetry is usually carried out after diges
trol It is also of interest to see in which form the sulfur
led. tion. Usually the samples are mineralized or combusted
is actually present. By using voltammetry the proportion by microwave digestion. Alternatively the metal ions can
of elemental sulfur can be determined directly and also be determined after extraction with a mine acid.
ral
simply. In this way inferences can be drawn about the
influence of gasoline on corrosion processes, for example,
regardng sensors in the fuel tank.
i
Copper in ethanol
Ethanol is used increasingly in gasoline as a blending
com
ponent. Contaminants can cause problems in the
engine. For example, traces of copper catalyze the oxida
tion of hydrocarbons. As a consequence, polymer com
pounds can form that can lead to deposits and block
ages in the fuel system. Using voltammetry, copper can
be measured without any sample preparation in pure
ethanol or ethanol-gasoline blends (E85, 85% ethanol
+ 15% gasoline) in the range between 2 µg/kg and
500 µg/kg.
Voltammetric determination of copper
24. Lab analysis on-line or at-line saves time and money
24 On-line and at-line Process Analyzers from Metrohm
Applikon are the preferred solution for process monitor
ence, we offer a wide range of analyzer products and
integrated systems for diverse applications and industries
ing in a wide range of industries. Using the complete to meet the challenging requirements and demands of
range of modern ion analysis (titration, KF titration, pho your process.
tometry, ISE standard addition, voltammetry, and direct
measurement), Metrohm Applikon Process Analyzers pro Metrohm Applikon is part of the Metrohm Group and
v
ide high precision results for any wet-chemical parame represented in over 35 countries. Our regional and local
ters you need right at your production line! presence offers knowledgeable support in sales, applica
tions, project engineering, and start-up. We intend to be
Metrohm Applikon has specialized in on-line and at-line cess monitoring partner for years to come.
your pro
process analysis for over 35 years. With this vast experi
Off-line lab analysis
• Manual sampling
• Sample transport to the lab
• Sample registration
At-line analysis
• Manual sampling
• Continuous manpower needed
• Automated lab analysis close to sampling point
inside plant
• Ideal where mutiple samples have to be taken at
several sampling points along the process
On-line analysis
• In-process measurement & response
• Automated sampling & registration
• Automated sample preconditioning
• Automated lab analysis
• Fast feedback of results
• Very limited manpower needed
• Close loop control
25. ProcessLab ADI 2045PL – at-line routine analysis in
production
The ProcessLab ADI 2045PL is by far the most robust rou
tine system for at-line analysis in everyday use in the plant
Process ab ADI 2045PL guarantees the highest level of
L
reliable analytical results. The new Process abManager
L
25
and control labs. Metrohm Applikon’s 35 years experi software offers a user-friendly interface in com i
b nation
ence with on-line analysis has resulted in a new system with the well proven tiamoTM lab software.
for custom made at-line process measurements. The
Determination of the total acid and total base Production of standard mixtures with a defined
numbers octane rating
The determination of the acid and base numbers is of The octane rating is a measure of a gasoline’s resistance
essential importance for the quality control of petroleum to engine knock. In order to assess the octane rating, the
products. The acid number records components that resistance to engine knock of a gasoline sample is deter
react acidically as a sum parameter and allows conclu- mined in comparison with standard mixtures showing a
sions concerning the corrosion of plant or engine com predefined octane rating. The standard mixtures, consist
ponents. Over the longer term, petroleum products with ing of n-heptane, isooctane (2,2,4-trimethylpentane) and
high base numbers offer protection from the corrosive toluene, must be prepared with the highest precision and
influence of any generated acids. By measuring sum pa correctness. ProcessLab is ideal for this thanks to its
ra eters, product alterations can be quickly and direcly
m t range of options for liquid handling. The automatic pro
recorded during use. duction of dilutions and dilution ranges as well as the
doping of additives can be carried out without any
The determination of acid and base numbers is carried further ado. The production of test mixtures is precisely
out automatically in the ProcessLab by potentiometric documented and the report can be used as a certificate.
titration in nonaqueous solvents. Because of its proximity
to the process, the analytical results are available within In the same way one can also prepare standard mixtures
minutes. for measuring cetane numbers with diesel fuels.
www.metrohm-applikon.com
26. On-line process analysis
26 In the (petro)chemical industry, continuous control of the
production process, the quality of the product and the
In many cases the IP66-NEMA4 housing of the analyzers
will be sufficient. In some cases in the petrochemical in
composition of any waste streams is of utmost impor dustry, however, explosion-proof systems are required.
tance. With the on-line process analyzers from Metrohm For those circumstances, the ADI 2040 is available in a
Applikon this is possible 24 hours a day, 7 days a week. stainless-steel explosion-proof version for Zone I or Zone
The analyzers are used directly on-site, as close as possible II according to the explosive atmosphere directives (ATEX).
to the process, and run completely stand-alone with out
operator intervention. The Metrohm Applikon analyzers
are based on wet-chemical analysis techniques such as
titration, photometry, or ion-selective electrode measure
ments. Analyzers are available for single method, single-
stream purposes as well as for complex multiple methods
and multiple streams.
In on-line analysis, sampling and sample preconditioning
are at least as important as the analyzer itself. Metrohm
Applikon has a lot of expertise in this area and is capable
of offering custom-made sampling systems, for example,
for pressure reduction, filtering, and degassing.
Analysis alone is of no use for process control, and that
is why the analyzers are all equipped with possibilities for
digital as well as analog outputs. Results, for example,
can be transferred via 4...20 mA outputs, whereas alarms
can be transmitted via digital outputs. Digital inputs, in
turn, can be used for remote start-stop purposes.
On-line Analyzer ADI 2045TI
27. Many of the analysis methods that are used in the labo
ratory can be transferred to an online analyzer. Typical
27
applications are:
Water content
A very important factor in quality control of the petro
chemical industry is the determination of the water
conent in oil. A too high water content has a negative
t
impact on the oil quality. As in the laboratory, Karl Fischer
titration (coulometry) is the method of choice for the
on determination of the water content in any oil
line Sampling system for determining the water
product. content in hydrocarbons
TBC in styrene
In styrene production, the addition of tertiary-butylcat
echol (TBC) as a stabilizer is critical to prevent the styrene
from polymerization during storage and transport. TBC
levels need to be maintained above 10...15 mg/L. The
prob is that the TBC concentration in styrene will
lem
slowly decrease in the presence of oxygen. Using an ADI
2040 with a colorimetric method, TBC levels can be
mo i
ntored continuously in order to maintain the concen
tration at the proper level.
Cuvette module for photometric measurements
Salt in crude oil
Excessive amounts of chloride salts in crude oil result in
higher corrosion rates in refining units and have a detri
mental effect on the catalysts used. Desalting techniques
are well established, but continuous control of the salt
content is needed for process control and cost reduction.
With the ADI 2040 equipped with special heavy duty
sample valves, the salt content can be monitored by
mea suring the conductivity or titration. After each analy
sis, the measurement vessel is cleaned and a blank meas
urement is performed before the next sample is taken.
For this type of application, the analyzers are configured
in an explosion-proof housing.
Hydrogen sulfide and mercaptane determination
Sulfur compounds in oil and oil products cause corrosion
and pose an environmental hazard. Determination of H2S
as well as mercaptans is done by titration with silver
nitrate, a sulfide-coated silver electrode serving as the
indicator electrode. www.metrohm-applikon.com
28. 28
Service you can rely on – Metrohm Quality Service
Reliable results for the lifetime of your analytical Metrohm Compliance Service
instruments Benefit from the Metrohm Compliance Service when it
From the inspection of the crude oil to the refining process comes to the professional initial qualification of your ana
and the quality control of the final products, chemical lytical instruments. Installation Qualification/Operational
analysis is in constant demand in the oil industry. Whoever Qualification carried out by our experts saves you time
is responsible in the laboratory for the accuracy of the and money, as your analytical system is configured ac
results must not make compromises. Fortunately, systems cordng to your needs and put into operation fast and
i
installed and maintained by professionals on a regular reliably.
basis all but eliminate the threats of instrument failure and
lost profits. Initial instructions and user trainings ensure error-free
opeation of your new instruments by your staff. The
r
Relying on the Metrohm Quality Service gives you peace Metrohm Compliance Service includes comprehensive
of mind from the very start. From the professional instal do
cumentation and guarantees compliance with the
lation of your instruments to regular maintenance care standards of quality management systems such as GLP/
and – should a failure ever occur – instant quality repairs, GMP and ISO.
we do everything to make sure that you can rely 100 per
cent on results produced during the entire lifetime of your
Metrohm instruments.
29. Metrohm Quality Service
Metrohm Quality Service is available worldwide. Pre
ven With a full service contract, for example, you can rely on
tive maintenance carried out on a regular basis extends the optimum performance of your Metrohm instruments,
your instrument’s lifetime while providing for trouble- incur no additional costs and benefit from complete and
free operation. All maintenance work done under the compliant verification documents. Thanks to our service
label Metrohm Quality Service is carried out by our own you are perfectly prepared for audits. 29
certified service engineers. You can choose the service
contract that suits you best.
An overview of Metrohm Quality Service
Our Services Benefit for the Customer
Metrohm Care Contracts that, depending on contract
type, include preventive maintenance, instrument Cost certainty and cost savings, coverage of repair
certification, on-site repair, free or discount on spare risk, quick response times and rapid problem solving,
sparts and consumables as well as guaranteed response minimal downtimes, and ideal preparation for audits
times.
Application support by means of our vast selection
of Application Bulletins, Applications Notes,
monographs, validation brochures, technical posters, Quick and professional solution to all arising application
and articles questions and complex analytical challenges
Personal consultation by our specialists per telephone
or e-mail
Competent users contribute substantially to reliable
Training courses
results
Accurate measurements
Certified calibrations, for example, of dosing and
Verification documentation for compliance with
exchange units
regulations and for efficient audits
Remote maintenance Expeditious resolution of software questions
Back-up support High data security
Short response times and thus, rapid problem resolution
Emergency service, for example, express on-site repairs
Minimization of downtime
Original spare parts, made in Switzerland and available Lasting, successful repair; short delivery times
world wide Minimization of downtime
Guaranteed spare parts available for at least 10 years Protection of your investment through long-term
beyond instrument discontinuation date availability of spare parts and accessories
Decentralized repair workshops located around the Quality repairs done quickly, so your instruments
world and a central workshop in Switzerland are ready for use again
30. Ordering information
30 Titration
2.848.3010 Oil Titrino plus
2.905.3010 Oil Titrando
2.855.2010 Robotic TAN/TBN Analyzer
2.864.1130 Robotic Balance Sample Processor TAN/TBN
6.0229.010 Solvotrode easyClean, 1 m cable
6.0229.020 Solvotrode easyClean, 2 m cable
6.0430.100S Ag-Titrode with Ag2S coating
6.1115.000 Optrode
6.6040.00X Application collection «Oil PAC»
Water determination according to Karl Fischer
Coulometric KF titration
2.831.0010 831 KF Coulometer including generator electrode with diaphragm and 728 Magnetic Stirrer
2.831.0110* 831 KF Coulometer including generator electrode without diaphragm
2.756.0010 756 KF Coulometer with built-in printer including generator electrode with diaphragm and
728 Stirrer (magnetic stirrer)
2.756.0110* 756 KF Coulometer with built-in printer including generator electrode without diaphragm
2.851.0010 851 Titrando including generator electrode with diaphragm and 801 Magnetic Stirrer
2.851.0110* 851 Titrando including generator electrode without diaphragm
2.852.0050 852 Titrando including generator electrode with diaphragm and 801 Magnetic Stirrer
2.852.0150* 852 Titrando including generator electrode without diaphragm
2.899.0010 899 Coulometer with built-in stirrer including generator electrode with diaphragm
2.899.0110 899 Coulometer with built-in stirrer including generator electrode without diaphragm
* The Magnetic Stirrer has to be ordered separately.
Volumetric KF titration
2.870.0010 870 KF Titrino plus
2.890.0110 890 Titrando with Touch Control
2.901.0010 901 Titrando including titration cell and indicator electrode
2.915.0110 915 Ti-Touch with built-in stirrer
2.916.3010 Oil Ti-Touch
KF Oven
2.860.0010 860 KF Thermoprep
2.874.0010 874 Oven Sample Processor
2.885.0010 885 Compact Oven Sample Changer
2.136.0200 KF Evaporator
Voltammetry
2.797.0010 797 VA Computrace for manual operation
MVA-2 VA Computrace system with automatic standard addition. Consisting of 797 VA Computrace
with two 800 Dosinos.
MVA-3 Fully automated VA Computrace system. Consisting of 797 VA Computrace with
863 Compact VA Autosampler and two 800 Dosinos for automatic addition of auxiliary
solutions. Allows the automatic processing of up to 18 samples. This system is the optimal
solution for the automatic analysis of small sample series.
31. 31
Oxidation stability
2.873.0014 873 Biodiesel Rancimat (230 V) including software and accessories
2.873.0015 873 Biodiesel Rancimat (115 V) including software and accessories
Ion chromatography
Anions and cations in «Produced water»
2.881.0030 881 Compact IC pro – Anion – MCS
2.881.0010 881 Compact IC pro – Cation
2.850.0910 2 x 850 Conductivity IC Detector
2.858.0020 858 Professional Sample Processor – Pump
6.2041.440 Sample Rack 148 x 11 mL
6.1006.430 Metrosep A Supp 4 - 250/4.0
6.1007.000 Nucleosil 5SA
6.6059.242 MagIC NetTM 2.4 Professional
Options
6.5330.000 Dialysis equipment
2.858.0030 858 Professional Sample Processor – Pump – Injector
2.800.0010 800 Dosino
6.3032.120 Dosing Unit 2 mL
6.2841.100 Washing station for IC Sample Processor
Anions in gasoline-ethanol blends
2.850.2150 850 Professional IC Anion – MCS – Prep 2
2.850.9010 850 Conductivity IC Detector
2.858.0010 858 Professional Sample Processor
6.2041.390 Sample Rack 16 x 120 mL
6.1006.630 Metrosep A Supp 7 - 250/4.0
6.1006.310 Metrosep A PCC 1 HC
6.1014.200 Metrosep I Trap column
6.6059.242 MagIC NetTM 2.4 Professional
Options
2.800.0010 800 Dosino
6.3032.210 Dosing Unit 10 mL
6.2841.100 Washing station for IC Sample Processor
Combustion IC
2.881.3030 Metrohm Combustion IC
6.1006.520 Metrosep A Supp 5 - 150/4.0
32. Subject to change
Layout Ecknauer+Schoch ASW, printed in Switzerland by Metrohm AG, CH-9100 Herisau
8.000.5080EN – 2012-07
petro.metrohm.com